The base of the case is a recycled switching supply case used in communication, very rigid. I used good quality parts, Mundorf main supply caps, Cardas connectors and wires for power, 6N single crystal/TFE wire for signal, AMP gold plated power connector, Vishay and PRP resistors, Wima, ROE caps, etc.

RA7, I did a few years back a two parts article on how to make your own PCB.
Files are kind of big. Send me a private email and I'll send you a copy.

I used to solder plate my pcb, now I used my ''special'' sprayed protection film to protect the copper. What is great about this stuff that is burn away when you solder the part. No need for a solder mask. For small smd parts, I install them first, then spray the stuff, finally I solder the bigger through hole parts.

6L6, I got the R-Core transformer from DIYclub, part R26-75, paid U$19.25 + shipping at the time...